Apparatus for forming screw threads



y 1929. J. v. PUQCINI ET AL 1,113,553 A APPARATUS FOR FORMING SCREW THREADS Original Filed Nov. 26, 1924 2 Sheets-Sheet 1 INV EN TORS 4 ATTOR EYS.

J. v. PUCCINI Er AL 1,713,553

APIEARATUS FOR FORMING SCREW THREADS Original Filed NOV. 26, 1924 2 Sheets-Sheet 2 Q, a Mum MAUI/42v J i [.w r I 6 2 May 21, 1929.

Patented May 21, 1929.

UNITED STATES PATENT OFFICE.

' JOSEPH ViRGIL PUCCINI "AND WILLIAM L. GUISE, F DOVER,

New JERSEY, ASSIGN- ORS TO HENRY THOMAS RICHARDSON, OF NEW YORK, N. Y.

APPARATUS FOR FORMING SCREW THREADS.

Original application filed November 26, 1924, Serial No. 752,364. Divided and this application filed January 13, 1926.

that the apparatus may be used over long periods of time and producedat relatively low cost.

Other objects of the invention will in part be obvious and will in part appear hereinafter. V r

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth and the scope of theapplicationof which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection'with the accompanying drawings, in which Figure 1 is a plan view of one form of apparatus of the type embraced in the present- 1nvention; I

Fig. 2 is a partly sectional front view thereof, showing a cover-plate WlllCll may be utilized in connection with this apparatus;

Fig. 3 is a partly sectional side view of the parts as shownin 2; and

Figs. 4. 5 and 6 are partly sectional side elevations of other forms of apparatus embodying the improved construction ofthe present invent-ion.

In the form of apparatus shown in Figs. 1,

2 and 3 the numeral 10 indicates a casing, which may have its side walls inclined towards each other, its upper and lower edges conforming to the contour of a cover and platform, respectively, which are applied thereto; This cover, in the present instance, includes a body 11 formed with an opening adjacent which an inwardly-extending flange or collar 12 is provided. Handles 13 are associated with the cover, and the latter may be 15 formed with cover. This platform to be formed in' the cast article.

Serial No. 80,861.

provided with pins 14 lying adjacent outer faces of the casing when the parts are assembled.

The platform preferably includes a plate perforations 16 and having upstanding lugs 17 which, similar to the pins 14, act to normally retain the'platform against displacement with respect to the is preferably formed with supporting legs or ribs 18'so that it is retained in spaced relationship with respect to the surface upon which it rests for a purpose hereinafter brought out.

The inner face of the collar or flange 12 is formed with a screw thread corresponding 1n pltch to the pitch of the thread which is A ring 19 is adapted to be'positioned within the collar, and to this end is formed with exterior screw threads corresponding to the threads of the latter. This ring is also formed with interior threads 20 corresponding exactly to the threads which are to be formed in the cast article. It will here be noted that the con volutions of this latter thread are of gradually decreasing circumference towards the outer edge of the ring, and that preferably the threaddoes' not commence immediately adjac'ent theinner edge thereof, but, rather, a blank space is left at this point, as has been indicated at'21. If desired, the upper edge of the ring may be formed with a series of openings22 toreceive the prongs 23 of' a wrench 24, the outer face of which may be knurled to afford anfadequate grip for the operators hand so that the ring may be turned. In order to close the outer end of the ring 19 the wrench may be removed and a coverplate 25 may be introduced into the space between the inneredges of the handles 13, this plate closely engaging the outer face of the cover 11 and preventing the escape of material through the bore of the ring. A

In utilizing apparatus of this character the ring is screwed into the collar to approximately the extent indicated in F ig. 2. 'I'hereafter. the cover-plate 25 is applied to the cover 11,

and the latter, together with the casing 10.

will be filled with this material, and the latter will extend into the threads 20. The platform may be applied to what is now the upper edge of the casing 10, and the position of the parts may be reversed to that shown in Figs. 2 and 3. Thereafter the cover-plate will be removed, and the ring 19 may be unscrewed from within the collar 12 by means of the wrench 24, or in any other suitable manner.

Incident to the fact that the convolutious of the thread 20 are of gradually increasing circumference towards the base of the ring, it will be obvious that if the latter is turned a coi'nparatively few times it will clear the threads formed in that portion of the core which extends into the ring bore, so that it is now practicable to remove the entire cover assembly,including the ring. If each convolution of the thread 20 is of the same circumference it will be understood that the ring will be removed entirely from within the col- 1 standard practice are of wedge shape, so that cast article.

a tight fit is assured when the parts are connected. Obviously, under the conditions existing in the illustrated embodiment the core will be a faithful reverse reproduction of the space within the casing and associated parts, and after the cover assembly has to be removed this core resting upon the platform may be placed in a treating chamber or oven 7 for the purpose of being hardened; it being obvious thatthe legs of the platform and the perforations formed therein will be conducive to having the heat or treating atmosphere act evenly over the entire lower face of the core.-

After the core has been treated it may be utilized in a'inold, either alone. or in conjunction with other cores, to produce, in the present instance, afemalescrew-threaded member having a wedge opening. V

lVith reference tothe form of apparatus shown in Fig. t the numeral 26 indicates an interiorly screw-threaded collar, which, similar to the collar or flange 12', has its screw threads of a pitch corresponding to the pitch of the threads which are to be formed in the Mounted within this collar is a ring 27, which has an effective height greater than that of the collar and which is formed 'with'exterior screw threads for engagement with the threads of the latter. The bore of be formed in the cast article, and this bore is 1 tapered to conform to what is usually accepted as the standard practice. It is to be noted that incident to-the fact that the ring is of a height in excess of the collar 26, as has been shown, it is not necessary to fully project the ring within the collar to have the inner edges of both of these members engage with a common supporting surface or plate 29.

In using this form of apparatus the parts are placed upon a plate 29 and are disposed in the 'manner'shown inFig. 4t. A mass of core-forming material 30 is packed within the ring 27, and thereafter this ring is turned with respect to the collar 26 so that the latter is lifted clear of the plate 29. It will of course be understood that the operator, during this actuation of the parts, will grip the col ar so .as to prevent a relative turning of the same with respect to the plate. At this time it will alsobe noted that the turning of the collar is preferably effected by having the same formed with an outwardly-extending flange 31, which may have its outer edge knurled in order to provide a suitable grip, this flange also servingas a stop limiting the movement of the ring inwardly with respect to the collar. The plate 29 embodies a suitable structure preventing a turning of the core 30 with respect to the plate under the last-named conditions of operation. For this purpose it may conveniently carry a spike 32, which extends into the mass of core material and is of course eccentrically disposed wit-h respectto the axis of the same. This last operation, i. e., the final turning of the ring, causes the material 30 to pack into the convolutions of the thread 28 so that no faults will occur incident to the failure of this material to properly key into this thread. It will be noted that the upper surface of the ring bore is plain or unthreaded', as at 33, and it will be understood that, as a consequence, this portion of the core will have a corresponding appearance.

By means of the flange-portion 31 the ring may now be unscrewed from within the collar 26, either wholly or else to an extent sufficient to cause the individual convolutions of the thread 28 to clear the corresponding convolutions of the core, whereupon the apparatus maybe lifted from the plate and the core may be placed in a treating chamber or oven. Thepurpose of the plain portion 33 will now be obvious in this form of core int-hat except for this portionof the core no securing portion would be provided, and it is usually desirable to have an excess core portion as the case of the core which would be produced by the form of apparatus'shown in Figs. 1, 2 and 3.

Now with'reference to the apparatus shown in Fig. 5, the numeral 3st indicates a collar corresponding to the collars in the preceding figure and being likewise formed with inte rior screw threads having apitch equal to the pitch of the threads whichare to be formed in the cast article. Extending into this collar and formed with corresponding threads upon its outer face is a ring 35, which furnishes the side wall of a cup-shaped member, thebody of which is generally indicated at 36. Adjacent its base this member may be formed with a knurled outer surface, and the outer surface of the collar may likewise be knurled. Thus these parts may be readily rotated withrespect to each other, and, if desired, the cup may be formed with a centrally-extending knurled stem 37 for its further manipulation. Projecting centrally within the body of the cup is a plug 38, which has its outer face formed with screw threads 39 corresponding exactly to the threads to be formed in the cast article, and the convolutions of this thread, in order to conform to standard practice, are of gradually decreasing diameter towards the inner end of the plug. The inner end of the plug in the present embodiment is concaved as at 40, and this plug is of a length less than the length of the side walls or ring-portion of the cup and the. height of the collar.

This apparatus is particularly intended for the manufacture of male cast articles having an exterior threaded portion, which, if the plug is tapered, will have a taper corresponding to standard practice. It will be obvious that in using the same the cup, after being screwed into the collar so that the parts assume the relative position shown in the figure in question, may be gripped by the handle or stem 37, and both of the same are in verted. Thereafter the entire interior of the cup is filled with core material, which is tightly packed in order to completely fill all voids and properly key into all recesses- A plate 41 is now applied to the outer edges of the collar and ring, and the entire apparatus is inverted to assume the position shown in Fig. 5. Thereupon an operator may grip the outside of the collar, and, by means of the stem or the knurled portion 37 of the cup, may turn the latter so that it is unscrewed from with in the collar. or, if the plug is tapered, until the thread 39 thereof clears the correspondingly threaded portion of the core. Thereafter the apparatus is removed and the core.

is left upon the plate, which latter is now transferred to a treating chamber or oven,

it being noted that in connection with the freeing of the core from the cup the inner faces of the ring or side wall 35 thereof are preferably tapered, so that a relatively small amount of axial movement of thecup away from the core will cause these parts to clear.

Finally, with reference to the form of apparatus shown in Fig. 6 it will be noted that the numeral 42 indicates the body of what might be termed a cup formed with adownwardly-extending flange portion 43, which may have its inner face tapered. The central portion of the cup base is formed with an opening, and an upwardly-extending internally threaded flange or collar 44 is positioned adjacent this opening, similar to the form of apparatus shown in Figs. 1, 2 and 3. This thread, as in the case of correspondingthreads in preceding forms of the apparatus, has a pitch corresponding to the pitch of the thread which is to be formed in the finished casting. Mounted within this collar and formed with threads 45 engaging the threads thereof is a plug 46, preferably having a knurled upwardly-extending flange 47 at its upper end. This flange, in addition to affording a convenient hand-grip by means of which the plug may be manipulated, also serves as a stop when it engages the upper edge of the collar in order to prevent the plug from being projectedto too great an extent into the interior of the collar. That portion of the plug which, when the parts are in the position shown in the figure, extends into the cup body is preferably tapered to correspond to standard practice, and it will be noted that the threads appearing upon this part of the plug body, in addition to corresponding to the pitch and that portion of the thread which engages the thread of the collar, should also correspond exactly to the thread which is to appear in the finished cast article.

In using this form of apparatus the plug is positioned within the collar and extends into the cap, as shown. The assemblage is then inverted and core-forming material is packed between the side walls of the cup and the plug. Thereafter, a plate 48 is applied to the open face of the latter, and the parts are reversed. The cup may now be prevented from rotating, and the plug may be unscrewed, it being observed that if the taper construction is htilized the plug threads will readily clear the core threads after the plug has been retracted a few turns. Thereafter the entire apparatus may be'lifted free of the core, and thelatter may be transferred upon the plate 48 to a treating chamber or oven. It will be understood that in this form of apparatus a male screw-threaded member will be provided when material is flowed around the core produced as above stated.

In allv forms of the apparatus it will be seen that a guiding member forms a part of the same, and by means of which that member which forms the threads in the core will be guided so as to prevent any possibility of distortion in the formed threads.

Since certain changes may be made in the above construction, and different embodiments of the invention could be made, without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which as a matter of language might be said to fall therebetween.

Having described our invention, What we claim as new and desire to secure by Letters Patent is:

1. An apparatus for forming cores and molds including a platform portion to receive molding material, a material enclosing member extending above said platform and having an inner face formed with screw threads and material impressing means rotatably mounted by said screw threads above said platform and being formed with a material-impressing thread.

2; A core-forming apparatus including a platform to supportmolding material, side walls extending upwardly therefrom, a cover portion associated with said side walls and being formed with an opening, a ring disposed within said opening and being formed with an interiorly screw-threaded bore and means for guiding the ring in its movements with respect to said cover.

3. A core-forming apparatus including a platform to support molding material, side walls extending upwardly therefrom, a cover portion associated with said side walls and being formed with an opening, a ring disposed within said opening and being formed with an interiorly screw-threaded bore, and the exterior of the ring and the face of. the

opening being formed with cooperating screw-threads.

4. A core-forming apparatus including a platform to support molding material, side walls extending upwardly therefrom and detachably associated therewith, a cover portion mounted by said side walls and being formed with a screw-threaded opening, a ring disposed within said opening and having exterior screw-threads to engage said first-named threads, and said ring being formed with an interiorly screw-threaded and tapered bore.

5. A core-forming apparatus including a platform to support molding material, side walls extending upwardly therefrom and detachably associated therewith, a cover portion mounted by said side walls and being formed with a screw-threaded opening, a

ring disposed within said opening and hav-' ing exterior screw-threads to engage said first-named threads, and said ring being formed with an interiorly screw-threaded and tapered bore, such latter thread terminating at'a pointimmediately adjacent the inner edge of said ring and spaced therefrom.

6. A core-forming apparatus including a platform to support molding material, outwardly flaring side walls extending upward ly from said platform, a transversely curved cover mounted bysald walls and the-upper edges of the latterbeingcurved to conform lar portion adjacent said opening and being formed with screw-threads on its inner face, a ring having exterior screw-threads to en gage said first-named threads, the bore of said ring being formed with screw-threads corresponding to those which are to be formed in the core and means above said cover and in detachable association with said ring for rotating the same with respect to said cover.

8. A device of the character described including a member to embrace a mass of molding material, a thread on the face of said member, a forming element having a thread engaging with the thread of saidmember and a shapmg thread forming a part of said element and for contact with said material, said element, when projected into said member, compressing said material into contact with the convolutions of said shaping thread.

9. A device of the character described in cluding a member to embrace a mass of molding material, a thread on the face of said member, a forming element having a thread engaging with the thread of said member and a shaping thread forming a part of said element and for contact with said material, said element, when projected into said member,

compressing said material into contact with the convolutions of said shaping thread and said shaping'thread having convolutions of constant gauge and decreasing circumference.

10. A device of the character described including amember to embrace amass of molding material, a thread on the face of said member, a forming element having a tapered surface and a constant surface, a thread formed in the latter surface and cooperating with the thread of said member and a shaping thread formed in the tapered surface of said element and for contact with said material, the tapered surface of said element being arranged when the latter is projected into said member to compress said material into contact with the convolutions of the shaping thread.

In testimony whereof we affix our signat-ures.

JOSEPH V. PUCCINI. WILLIAM L. GUISE. 

